Define Group O or The noble gases.

Define Group O or The noble gases. 

Group O - The noble gases:

Q. What do you call a chemical element with no chemistry?

A. A noble gas.

The most striking thing about this family of elements is their lack of reactivity.

They used to be called the inert gases. Inert means 

'having no reactions'.

However, in 1962 their first compound was made.

They were then re-named the noble gases.

 

The noble gases are so unreactive that they are found as the atoms themselves.

They are called monatomic gases ('one-atom' gases).

The noble gases are very unreactive.

Why are the noble gases so unreactive?

The noble gases are stable because their outer shells are full.

With full outer shells, atoms are stable.

 

The boiling points (or boiling temperatures) of the noble gases increase going down the group.

The density of the noble gases increases going down the group.